Examples for 8th grade - page 3

  1. Percent calculation
    percent_sign Calculate 22% if 68% is 42.
  2. Trapezoid
    rectangular_trapezoid Are diagonals in a rectangular trapezoid perpendicular and bisect the angles?
  3. Road
    cesta Between cities A and B is route 3 km long of rise average 4‰. Calculate the height difference of cities A and B.
  4. Painter Pavel
    pixla_s_farbou Painter Pavel painted the fence for 20 hours and painter Petr the same fence painted for 17 h. How long should take painted the fence together?
  5. KLMN
    trapezium In the trapezoid KLMN is given this informations: 1. segments KL and MN are parallel 2. segments KL and KM has same length 3. segments KN, NM and ML has same length. Determine the size of the angle KMN.
  6. Right Δ
    ruler Right triangle has length of one leg 7 cm and length of the hypotenuse 25 cm. Calculate the height of the triangle.
  7. Cylinder - h
    cylinder_2 Cylinder volume is 129 cm3. Base radius is 3 cm. Calculate the height of the cylinder.
  8. Center traverse
    trianles It is true that the middle traverse bisects the triangle?
  9. Christmas Day
    stedryd In leap years was 53 Sundays. On what day of the week fell to Christmas Day?
  10. Workers
    workers Two workers fulfill a certain task when working together for 7 days, the first if he worked himself done work in 18 days. How many days will do whole job a second worker?
  11. AVG of INT
    seq_moon What is the average of the integers from 7 throuht 15 inclusive?
  12. Beer
    piva After three 10° beers consumed in a short time there are 7.4 g of alcohol in 5 kg adult human blood. How much is it per mille?
  13. Coin and die
    die Flip a coin and then roll a six-sided die. How many possible combinations are there?
  14. Diofant 2
    1diofantos Is equation ? solvable on the set of integers Z?
  15. MO SK/CZ Z9–I–3
    ball_floating_water John had the ball that rolled into the pool and it swam in the water. Its highest point was 2 cm above the surface. Diameter of circle that marked the water level on the surface of the ball was 8 cm. Determine the diameter of John ball.
  16. Diagonal
    rectangle_diagonal Calculate the length of the diagonal of the rectangle ABCD with sides a = 7 cm, b = 6 cm.
  17. Chickens and rabbits
    pipky In the yard were chickens and rabbits. They had 44 heads and 124 legs. How many chickens and how many rabbits was in the yard?
  18. Ladder
    rebrik_1 Ladder 5 m long is leaning against the wall. It foot is 0.9 m away from the wall. In which height ladder touch the wall?
  19. Saving
    cars Kevin save € 4620 to buy a car. Yet it lacks save 65% of the car price. How much is the car?
  20. Number
    sqrt_2 Is number 4.764023 irrational?

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.



To this e-mail address we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.